WP_Error, validation (ok)

function registration_validation($role, $fname, $lname, $email, $password) {
  global $reg_errors;
  $reg_errors = new WP_Error;
  if (empty($fname) || empty($lname) || empty($email) || empty($email)) {
    $reg_errors->add('field', 'Required form field is missing');
  }
  if (4 > strlen($username)) {
    $reg_errors->add('username_length', 'Username too short. At least 4 characters is required');
  }
  if (username_exists($username)) {
    $reg_errors->add('user_name', 'Sorry, that username already exists!');
  }
  if (!validate_username($username)) {
    $reg_errors->add('username_invalid', 'Sorry, the username you entered is not valid');
  }
  if (5 > strlen($password)) {
    $reg_errors->add('password', 'Password length must be greater than 5');
  }
  if (!is_email($email)) {
    $reg_errors->add('email_invalid', 'Email is not valid');
  }
  if (email_exists($email)) {
    $reg_errors->add('email', 'Email Already in use');
  }
  if (!empty($website)) {
    if (!filter_var($website, FILTER_VALIDATE_URL)) {
      $reg_errors->add('website', 'Website is not a valid URL');
    }
  }
  if (is_wp_error($reg_errors)) {
    foreach ($reg_errors->get_error_messages() as $error) {
      echo '<div>';
      echo '<strong>ERROR</strong>:';
      echo $error . '<br/>';
      echo '</div>';
    }
  }
}